Introducing e-learning/teaching in a physiology course for medical students: acceptance by students and subjective effect on learning.

Retrieval of information has substantially changed within the last two decades. Naturally, this has also affected learning/teaching techniques, and methods that are commonly referred to as "e-learning" have become an important part in modern education. Institutions have to decide if (and how) to implement this new form of teaching but face the problem that little subject-specific research has been published for different teaching modes and methods. The present study compares a course module of the physiology laboratory course for medical students in the preclinical phase before and after the introduction of computer-aided course instructions (CACI). Students were provided with an online questionnaire containing Likert items evaluating workspace redesign, acceptance of course instructions, incentive to actively participate in the course, and subjective gain of knowledge. CACI was clearly preferred over the previously used paper workbook. However, the questionnaire also revealed that the gain in knowledge, as subjectively perceived by the students, had not improved, which is in agreement with several studies that neglected a beneficial effect of e-learning on learning success. We conclude that the CACI meet today's student's expectations and that introducing this system seems justified from this perspective.

Combining atomic force-fluorescence microscopy with a stretching device for analyzing mechanotransduction processes in living cells.

Mechanical forces affect biological systems in their natural environment in a widespread manner. Mechanical stress may either stimulate cells or even induce pathological processes. Cells sensing mechanical stress usually respond to such stressors with proliferation or differentiation. Hence, for in vitro studies, the ability to impose a controlled mechanical stress on cells combined with appropriate analytical tools providing an immediate answer is essential to understand such fundamental processes. Here, we present a novel uniaxial motorized cell stretching device that has been integrated into a combined fluorescence microscope (FM)-atomic force microscope (AFM) system, thereby enabling high-resolution topographic and fluorescent live cell imaging. This unique tool allows the investigation of mechanotransduction processes, as the cells may be exposed to deliberately controlled mechanical stress while simultaneously facilitating fluorescence imaging and AFM studies. The developed stretching device allows applying reproducible uniaxial strain from physiologically relevant to hyperphysiological levels to cultured cells grown on elastic polydimethylsiloxane (PDMS) membranes. Exemplarily, stretching experiments are shown for transfected squamous cell carcinoma cells (SCC-25) expressing fluorescent labeled cytokeratin, whereby fluorescence imaging and simultaneously performed AFM measurements reveal the cytokeratin (CSK) network. Topographical changes and mechanical characteristics such as elasticity changes were determined via AFM while the cells were exposed to mechanical stress. By applying a cell deformation of approx. 20%, changes in the Young's modulus of the cytoskeletal network due to stretching of the cells were observed. Consequently, integrating a stretching device into the combined atomic force-fluorescence microscope provides a unique tool for dynamically analyzing structural remodeling and mechanical properties in mechanically stressed cells.

A prospective observational study of the efficacy of a novel hydroactive impregnated dressing.

OBJECTIVE: To assess the clinical efficacy, tolerance and acceptance of a novel, hydroactive-impregnated dressing (Hydrotul) in the local treatment of acute and chronic wounds. METHOD: In a prospective observational study 24 centres in France, Belgium, Germany and Austria recruited 74 patients. At each dressing change the investigators evaluated the condition of the wound, perilesional skin and patient-reported pain. Overall, five dressing changes were documented, or until complete healing occurred. The hydroactive properties of the dressing were assessed in laboratory tests by measuring fluid absorption capacity and kinetics. RESULTS: Patients were treated for an average of 17 days. The wound condition improved markedly during the observation period. The wound area covered with fibrinous slough decreased from 29% to 14%, epithelialisation increased from 19% to 54% and 22 wounds were completely healed by the end of the study. The number of patients reporting severe and moderate wound pain decreased from 35% to 19% and the proportion of patients without wound pain doubled from 27% to 60%. In laboratory tests, Hydrotul absorbed two to three times the amount of fluid compared with other impregnated wound dressings and the kinetics of absorption was much faster. CONCLUSION: The novel hydroactive impregnated dressing supports the healing process in patients with acute and chronic wounds and reduces wound pain. The dressing absorbs excess wound exudate while keeping the wound surface moist and protecting perilesional skin.

Merged screening for human immunodeficiency virus Tat and Rev inhibitors.

In addition to "conventional" drug discovery targets used in modern strategies, mainly focusing on proteins, recent insights into gene regulation as a novel drug concept have begun to invite the targeting of biomolecular interactions between proteins and RNA. Because two protein-RNA interactions (Tat and trans-activation-responsive element, Rev and Rev-responsive element) are essential for any productive replication of human immunodeficiency virus, this important human pathogen was used as a model system for our studies. The design of a fluorescence-based high throughput assay, in which both targets were presented in the same vessel, enabled us to simultaneously interrogate two characteristics of a potential inhibitor: potency of interference and selectivity toward each of the interactions. Although related systems have been reported for several DNA binders, an extension into interference with transcription events would open a new dimension of cellular regulation. Here we describe the setup of the screening assay for over 110,000 compounds as well as a primary characterization of identified hits. The assay's characteristics demonstrate that a microwell-based dual screening system for RNA binders may add a powerful tool to modern drug discovery.

Development, chemistry, and physical properties of iopamidol and its analogues.

A series of 5-hydroxyacylamino-2,4,6-triiodo-N,N'-hydroxy-alkyl-isophtalamides was prepared in order to study the structural requirements for high water solubility and low toxicity. Among the amides substituted by 2-hydroxyethyl; 2,3-dihydroxypropyl; 1,3-dihydroxypropyl-; and 1,1-dihydroxy-methyl-2-oxyethyl- groups, the highest water solubility was obtained with the 1,3-dihydroxypropyl- group. Neither optical resolution of the 2,3-dihydroxypropyl moiety nor amide formation with two different amines improved the water solubility. The optimal solubility was obtained with S-5-alpha-hydroxypropionylamino-2,4,6-triiodoisophtalic acid di-(1,3-dihydroxy-2-propylamide), iopamidol. Iopamidol forms anhydrous and monohydrate crystals, characterized by differential thermal analyses, x-ray diffraction patterns, and solubility patterns. A method for enzymatic assay of the optical purity of iopamidol with lactodehydrogenase is described as well as partition coefficient, ionization constant of the oxyacylamido-group, critical micelle formation, surface tension, and osmolarity.

Molecular rearrangement of 5-(a-hydroxy-alkanoylamino)-2,4,6-triiodo-isophthalic acid amides.

Iomeprol, a new nonionic contrast agent, undergoes in alkaline solution a Smiles-type intramolecular rearrangement to give 5-methylaminocarbonylmethoxy-2,4,6-triiodoisophthalic acid-bis-(2,3-dihydroxypropylamide). The rearranged product was isolated and its structure confirmed by spectra and by synthesis. The reaction is reversible and could be extended to some structurally related compounds.

Iopamidol: new preclinical and clinical data.

Iopamidol was rapidly eliminated from the central nervous system of dogs (greater than 90% in 24 hours). In rabbits, renal excretion involved tubular mechanisms at low blood levels, and predominant glomerular filtration at higher levels. Injection of iopamidol into the right atriums of rabbits produced hemodynamic effects similar to those of other contrast media, but less severe. The effect of iopamidol on peripheral vascular resistance was significantly lower than that of metrizamide. Iopamidol was found useful in clinical neuroradiology and angiography.

A liposomal contrast agent. Preliminary communication.

Iopamidol-carrying liposomes were studied as potential hepatosplenographic contrast agents. Large unilamellar vesicles (0.3-1 mu) prepared from phosphatidylcholine:Dipalmotylphosphatidic acid (PC:DPPA) 9:1 and 300 MgI/mL iopamidol solution showed favorable entrapment measured as mg entrapped iodine/mg lipids (I/L). The effect of extrusion through polycarbonate membranes on liposome characteristics and in vivo distribution was investigated. Extrusion above the transition temperature of lipids reduced the average size and size distribution and increased the I/L ratio. Distribution studies of extruded and nonextruded liposomes in rats demonstrated different behavior of the preparations; extruded liposomes showed higher spleen uptake than did unextruded, while liver uptake was comparable; lung entrapment, observed with unextruded particles, was almost eliminated with extruded liposomes. Preliminary imaging studies in rats were carried out at a dose of 250 mgI/kg; typical computed tomography (CT) scans of the liver demonstrated contrast enhancement of greater than or equal to 60 HU from 90' up to 240' after injection.

B-19036, a potential new hepatobiliary contrast agent for MR proton imaging.

B-19036 is an octadentate chelate of the paramagnetic ion Gd3+ under investigation as a proton relaxation enhancer (PRE) in magnetic resonance (MR) proton imaging. Its relaxivity was determined at 0.5 T by pulse spectrometry in various biologic fluids and in liver tissue homogenate. The ligand selectivity versus gadolinium was assessed in comparison with that versus other ions of biologic interest. Acute toxicity was determined after intravenous (IV) and intracerebral administration to mice. Pharmacokinetic studies conducted in rats indicated that unlike Gd-DTPA, where excretion is exclusively renal, biliary route plays a significant role in the excretion of B-19036, suggesting its possible use for hepatobiliary imaging.

Self-care agency and blood pressure control.

This research examined whether blood pressure measurement relates to an individual Self-Care Agency's (SCA) capabilities (self-concept, knowledge, and initiative) to exercise self-care. A sample of 110 hypertensive high-risk urban black Americans (61 males and 49 females) with a mean age of 46 years (range 18-75), was administered the 43 item 'Exercise of Self-Care Agency' scale and a demographic/health questionnaire. The blood pressure (BP) of each participant was measured at the time of the survey. A large number of subjects (72%) had normal BP and 80% low SCA capability scores. Twenty-eight percent had abnormal BP and 21% had high SCA scores. Blood pressure did not relate to self-care agency. The SCA subconstruct, 'Initiative' was significantly related to normal BP (r = 0.3354, P = 0.006). Self-care agency was inversely associated with obesity, cigarette smoking and excessive salt use. These findings suggest a deficit relationship between SCA and therapeutic self-care demand among urban black Americans who are at high risk for hypertension.

Quantitative evaluation of myelinated nerve fibres and hair cells in cochleae of humans with age-related high-tone hearing loss.

In this study 9 human temporal bones from 8 individuals were fixed with Karnovsky solution by perilymphatic perfusion within 1-3 h after death and examined using the "block-surface method' (Spoendlin and Brun, 1974; Spoendlin and Schrott, 1987) and the "micro-dissection method' (Johnsson and Hawkins, 1967). The audiogram of 7 individuals showed high-tone hearing loss, typical for sensory-neural presbycusis. The inner (IHC) and outer hair cells (OHC) and the myelinated nerve fibers in the osseous spiral lamina were counted to correlate audiometric curves with hair-cell and nerve-fibre densities. The "block-surface' method allows accurate hair-cell and myelinated nerve-fibre enumeration with maximal preservation of cochlear structures. The most significant change in the cochlea was not the expected loss of hair cells but an evident loss of nerve fibres in the spiral lamina along the entire length of the cochlea. This loss of nerve fibres was found to be age-related. Reductions up to 30-40% in comparison to normal-hearing middle-aged persons were found in cochleae from persons older than 60 years. In 2 cases only 13% of the fibres remained in some regions of the cochlea. The hair-cell counts showed a reduction of approximately 80% of the OHCs, mainly in the apical parts of the cochlea, and only little differences in the number of IHCs as compared with a group of normal-hearing middle-aged persons. We conclude that neither loss of hair cells nor primary degeneration of nerve fibres alone can fully explain the high-tone loss. Probably injuries of hair cells or neuronal elements at the cellular level can cause threshold elevation.

Quantitative evaluation of cochlear neurons and computer-aided three-dimensional reconstruction of spiral ganglion cells in humans with a peripheral loss of nerve fibres.

Quantitative data on human cochlear neuronal elements were collected from various regions in five patients with high-tone hearing loss due to presbycusis and in two patients with normal hearing. The number of nerve fibers was assessed in the spiral lamina and in the inner acoustic meatus together with counts of spiral ganglion cells. The results show that the number of neurons decreased peripherally, i.e., with increasing distance from the central nervous system in patients with high-tone hearing loss due to presbycusis. In two patients with normal hearing no significant difference in the number of neurons was found in the lamina spiralis as compared to the inner acoustic canal. Computer-aided 3-dimensional reconstruction of the human spiral ganglion displayed large bipolar neurons (type I cells), but also large ganglion cells with one missing axon. The results may indicate that a slow retrograde degeneration occurs from the periphery towards the spiral ganglion in presbycusis. Transmission electron microscopy analysis of freshly fixed human spiral ganglions displayed interneural connections. It is speculated whether a trophic supply from other neurons at the level of the spiral ganglion can prevent or delay further degeneration of the central axon.

Selective aspects of human pathology in high-tone hearing loss of the aging inner ear.

Accompanied with aging, the thresholds for high frequency sounds may elevate and result in a progressive hearing loss described as presbycusis. Based on correlations between audiometric measures of aged patients and histologic findings garnered from postmortem examinations, four types of presbycusis have been characterized: sensory-neural, neural, strial, and conductive [Schuknecht, H.F., Gacek, M.R., 1993. Ann. Otol. Rhinol. Laryngol. 102, 1--16]. Otopathologic changes to the inner ear as a direct function of age, however, remain controversial. The focus of this investigation involves the pathological impact on remaining sensory structures in patients having sensory--neural degeneration. The current study presents seven human temporal bones extracted from patients aged 53--67 years with high-tone hearing loss and with no known history of extraordinary environmental events involving head or noise trauma, acoustic overstimulation, or ototoxicity. In previously published findings of these specimens, all but one temporal bone failed to demonstrate a meaningful correlation between audiometric measurements and loss of functional hair cell populations with secondary retrograde degeneration of nerve fibers. Using the block surface method, electron microscopic micrographs demonstrate ultrastructural changes in the cuticular plate, stereocilia, pillar cells, stria vascularis, and the spiral ligament. In all pathological specimens, the greatest incidence of degeneration was seen at the cuticular plate. Conclusively, our findings present three implications in the aging human cochlea: firstly, audiometric measures that represent a high-tone hearing loss may take various forms with respect to ultrastructural patterns of degeneration and surviving structures; secondly, the incidence of lipofuscin and lysosome granules does not correlate with the degree of hearing loss and; thirdly, as shown only in guinea pigs [Anniko, M., 1988. Scanning Microsc. 2, 1035--1041], high-tone hearing loss can be associated with deformation of the cuticular plate.

Automated procedure for determination of free aromatic amine in water-soluble radiopaques.

The determination of free aromatic amine in water-soluble radiopaques by diazotization in 2-methoxyethanol-water, coupling with naphthylethylenediamine, and colorimetry of the azo dye has been automated. Sensitivity, precision, and accuracy are satisfactory for purity testing and stability studies.

Radiopague contrast media. Part 30. New heterocyclic derivatives of triiodophenoxy alkanoic acids.

A series of new heterocyclic derivatives of triiodophenyl and triiodophenoxy alkanoic acids was prepared; some of these compounds showed high billiary excretion and low acute toxicity in rats. One compound, 2-ethyl-3-[3-N-butyrolactamyl-2,4,6-triiodophenyl]-propionic acid, showed such characteristics that encouraged us to carry out further preclinical and clinical investigations.

Baccalaureate and associate degree student nurses' cultural knowledge of and attitudes toward black American clients.

The purpose of this study was to investigate the effect of cultural diversity education in nursing on baccalaureate and associate degree students' cultural knowledge of and attitudes toward black American clients. Cultural diversity education in nursing information processing, and attitude concepts (Fishbein & Ajzen, 1975) provided the conceptual framework. The sample consisted of 110 baccalaureate and associate degree senior and freshmen students from National League for Nursing accredited schools of nursing. Each school's dean confirmed that cultural diversity educational experiences were included in the curricula. The findings indicated that the group of associate degree students, which included a large number of various ethnic students, had higher cultural knowledge of black American clients then the baccalaureate degree students, who had less ethnic variance. However, adjustment for the ethnic variable was not significant (F(1,1) = 12.5, p less than .001). There were no differences in the attitudes toward black American clients between the two groups of students. The score ratings for cultural knowledge of (m = 66.90 on a scale of 0 to 100), and attitude toward (m = 35.40 on a scale of 7 to 56 points) black American clients were low in each group of students. Implications are for increased and improved cultural content in nursing education and alternative methods of teaching black American cultural content.

The nursing cultural center. A design for cultural diversity.

The rationale for the development of the Nursing Cultural Center (NCC) at a leading mid-western university is discussed by the author. Both the goals and purposes of the NCC within the framework of the mission of the University of Wisconsin-Milwaukee and the surrounding community are emphasized to illustrate how two basic strategies are used to facilitate the accomplishment of these goals and purposes. These strategies are processing cultural health information and implementing the Cultural Diversity Practice Model (CDPM). The NCC is a cultural health informational center which facilitates the application of the Cultural Diversity Practice Model developed by the author.

Meeting the challenge of mentoring African American nursing faculty: a strategy for professional development.

Is mentoring just another bandwagon for African American and minorities to jump on? My personal perspective is that we should examine in more detail and dialogue the notions of self-actualization and affirmation that several authors identified as the essence of mentoring minorities. Then, particular distinctions among concepts such as mentor, master role model, preceptor, "buddy," or whatever might be seen as variations on the main theme of personal and professional self-actualization. Given what it may accomplish, appropriate mentoring for the African American nursing faculty neophyte is a challenge for the nursing profession and a strategy for institutional advancement in the twenty first century.

Integrating cultural diversity theoretical concepts into the educational preparation of the advanced practice nurse: the Cultural Diversity Practice Model.

Educational preparation of the Advanced Practice Nurse (APN) for the challenging role of providing available and accessible health care to ethnic diverse populations requires that cultural diversity be included in the expanded education. The Cultural Diversity Practice Model is offered for that purpose.